Biomedical Engineering and Bioengineering Commons^™

Three-Dimensional Stress Analysis Of The Femur With Prosthetic Hip Stem Utilizing Computed Tomography Scans Of The Femur For Geometry And Material Properties, Thomas J. Lavin

Theses

Three-dimensional finite element stress analyses of the femur with prosthesis hip stem were performed for two cases, one male and one female, using ideally bonded cemented titanium prostheses. Computed tomography data files were used to derive the three-dimensional femur geometry and material properties for each cortical bone element. The maximum shear stress (4.7 MPa) in the cement was greater then the maximum tensile stress and occurred at the cement-bone interface. The tensile stresses in the cement were less then the fatigue strength of the cement. The stress patterns were quite similar for the two cases.

A data analysis program was …

Simulating The Distribution Of Axon Size In Nerves, Robert B. Szlavik, Hubert De Bruin

Biomedical Engineering

The electrical excitation threshold of a nerve axon is dependent upon the physical properties of the axon membrane as well as the axon diameter. Histological studies have confirmed that peripheral afferent muscle nerves have a characteristic distribution of axon diameters. We approximate a probability density function for this distribution that consists of the summation of several Gaussian functions. A transformation technique is then applied for the random generation of the nerve axon diameters from uniformly distributed random numbers. For the example presented, the resultant distribution of peripheral afferent muscle nerve axon diameters conforms approximately to the characteristic distribution that has …

Corrosion Fatigue Crack Growth Behavior Of Aircraft Materials, Tarun Goswami, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The effects of test parameters on the corrosion fatigue crack growth behavior of structural materials have been examined in this paper. Test parameters such as stress ratio, frequency, hold time, temperature, pH level of the media, and other parameters are known to alter the corrosion fatigue crack growth rates in structural materials. Numerous laboratory test variables that affect the crack growth and/or corrosion growth rates, which in an operating environment of an aircraft are not characterized, are reviewed. A summary of such information may help determine the inspection intervals of the new and aged airplanes, perform the inspections, and develop …

Review Of Pit Nucleation, Growth And Pitting Corrosion Fatigue Mechanisms, Tarun Goswami, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

This paper presents a review of the state of the art developments in the pitting corrosion fatigue of aircraft structural materials. Mechanisms that govern the nucleation and growth of pitting and corrosion fatigue (CF) are briefly addressed. Some of the developments made in the author's laboratories in proposing the fretting induced pit nucleation and growth mechanisms, analysis of the hidden corrosion constituents in fuselage joints and pitting corrosion fatigue crack growth (PCFCG) model are elucidated. An epistemology of the topic is presented which will be of assistance to the community working in this area.

Transformation Of Tnt By Aquatic Plants And Plant Tissue Cultures, Joseph B. Hughes, Jacqueline V. Shanks, Mindy Vanderford, John Lauritzen, Rajiv Bhadra

Jacqueline V. Shanks

The ability of plants to uptake and transform 2,4,6-trinitrotoluene (TNT) was investigated using the aquatic plant Myriophyllum spicatum, axenic Myriophyllum aquaticum, and Catharanthus roseus hairy root cultures. Studies demonstrate that Myriophyllum, with or without its periphyton, and C. roseus transform TNT. Low concentrations of aminated nitrotoluenes (2-amino-4,6- dinitrotoluene and 4-amino-2,6-dinitrotoluene) were observed in the extracellular medium and tissue extracts. Primary products of transformation were not identified, and mineralization was not observed. Mass balances demonstrate that a large percentage of the unknown TNT transformation products were associated with the plant. This fraction could be at least partially recovered from the plant …

Sintered Carbonate Apatites As Bone Substitutes, Yutaka Doi

Cells and Materials

Sintering of carbonate apatites was investigated and the usefulness of sintered specimens as bone substitutes was evaluated in vitro and in vivo. Osteoclasts appeared to be capable of resorbing sintered carbonate apatite, which was as soluble as deproteinated bone and much more soluble than sintered hydroxyapatite in weak acids. In skull defects of Wistar rats, sintered carbonate apatite particles resorbed to an appreciable extent, but the rate of resorption did not exceed that of new bone formation. At 4 weeks after implantation the defects were filled almost completely with new bone that compared favorably with the host bone. These …

Laser Profilometry Of Polymeric Materials, Eduard A. Kulik, Patrick Calahan

Cells and Materials

Unlike the mechanical stylus profilometer, the laser profilometer does not damage the surface of soft materials. However, the accuracy of autofocusing of the laser profilometer is not always sensitive enough to discriminate the material/air interface from subsurface structures of semitransparent polymers. In the present study over ten polymeric surfaces were gold coated in order to investigate the effect of gold coating on the readings of a laser profilometer. Surface profiles of some polymeric materials became much smoother even if a very thing gold coating was applied to increase the reflection from the surface. It was concluded that a thin gold …

Image Analysis Of Primary Bone-Derived Cells On Different Polystyrene Surfaces, R. M. Shelton, G. Landini

Cells and Materials

The aim of the present study was to examine whether two different cell populations could be discerned using image analysis of a variety of morphological parameters on bacteriological and tissue culture polystyrene surfaces. Rat periosteal and osteoblast cultures were established on both polystyrene petri dishes and examined using phase contrast microscopy after one and two weeks before capturing digital images which were stored on a personal computer. The digital images were processed to identify the cell margins or perimeter, from which seven different morphological parameters were calculated using a program developed (by GL) for both the cell populations on the …

Corrosion Of Metal Hip Arthroplasties And Its Possible Role In Loosening, H. K. Koerten, J. J. A. M. Van Raay, J. J. M. Onderwater, F. P. Bernoski, P. M. Rozing

Cells and Materials

Tissue removed with human hip arthroplasties during revision surgery of 45 patients was evaluated by transmission electron microscopy and X -ray microanalysis (XRMA). The results show that microscopic and submicroscopic particles are abundantly present in the tissue at the tissue/implant interface. XRMA of individual particles shows that the chemical composition of a portion of the particles was in agreement with that of the retrieved implants. Regularly, particulates with a dissimilar chemical composition were found. Sometimes, these particles could be recognized as filler particles of the cements used. Other particles could partly or completely be composed of the chemical elements that …

Bone Marrow Cell Colonization Of, And Extracellular Matrix Expression On, Biodegradable Polymers, C. E. Holy, M. S. Shoichet, J. E. Davies

Cells and Materials

Poly(DL-lactide-co-glycolide)s (PLGAs) have been proposed as substrata for bone tissue engineering. In the experiments reported herein, we sought to identify the optimum lactide to glycolide ratio, from the series 85:15, 75:25, 50:50, or poly-(DL-lactide) (PLA), for the elaboration of bone matrix by cultured rat bone marrow cells (RBMC) on two-dimensional substrates. Having identified PLGA 75:25 as the optimum for bone matrix elaboration by RBMC, we produced three dimensional foams from this copolymer. For the two dimensional substrata, glass coverslips were spin-coated with one of the PLGAs, or PLA. Cultures were maintained for two weeks. We employed a new technique to …

Macrophage Response To Polymethylmethacrylate Particles, Stephen M. Horowtiz

Cells and Materials

This paper reviews studies performed by this laboratory involving the macrophage response to implant particles. Through the development of a tissue culture model, we have studied the events which occur following macrophage phagocytosis of bone cement particles, the released mediators and cell interactions which may ultimately lead to bone resorption, and the inhibition of this process with the use of pharmaceutical agents. This is divided into the following sections: Histologic response of macrophages to cement particles I toxicity I and mediator release, the effects of particle size and composition on mediator release by macrophages, macrophage I osteoblast interactions, macrophage I …

Heat-Treatment Behavior Of High-Palladium Dental Alloys, Qiang Wu, William A. Brantley, John C. Mitchell, Stanley G. Vermilyea, Jianzhong Xiao, Wenhua Guo

Cells and Materials

Four high-palladium dental alloys were cast, quenched following solidification, and heat treated at temperatures ranging from 200° to 1,800°F. The Vickers hardness of each alloy was measured, and microstructural changes were studied by scanning electron microscopy (SEM). Phase transformations were investigated by thermomechanical analysis (TMA). Heat treatment at 1,600° and 1,800°F significantly decreased the hardness of one Pd-Cu-Ga alloy, compared to the as-cast condition, as did heat treatment at 1,800°F for the other Pd-Cu-Ga alloy and one Pd-Ga alloy, and yielded fine-grained microstructures of the palladium solid solution. There were generally no significant changes in the hardness of the other …

Fracture Of An Acetabular Component Inserted Without Cement: A Case Report, R T. Trousdale, D J. Berry, Joshua J. Jacobs, Jeremy L. Gilbert

Biomedical and Chemical Engineering - All Scholarship

No abstract provided.

Dwell Sensitivity Fatigue Behaviour Of High Temperature Materials, Tarun Goswami, G. R. Halford, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The dwell sensitivity fatigue behavior of six high temperature materials is examined in this paper: two stainless steels, 304L and 304, two tantalum alloys, Τ- Ι 11 and ASTAR 811C, pure nickel Ni 201 and a single crystal nickel-base superalloy, PWA 1480. The stainless steel alloys were found to be tensile dwell sensitive; however, a saturation in dwell sensitivity was found with the increase in strain range for all materials examined. At lower strain ranges the dwell cycles were producing lower lives than at higher strains, as found in the case of AISI SS 304 and two tantalum based alloys, …

A New Model Of High Temperature Low Cycle Fatigue Life Prediction - Applicability With Low Alloy Steels, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Creep-fatigue data on low alloy steels were collected from National Research Institute for Metals (NRIM) Tokyo, Japan. These data were generated for lCr-Mo-V, 2.25Cr-Mo, and 9Cr-lMo steels under a wide range of test conditions. A new creep-fatigue life prediction method was developed and data compiled were assessed to examine the applicability of the new method. A brief review of the empirically based, phenomenological life prediction methods was presented where no method was found to be applicable universally to all the creep-fatigue data. The new model was developed within the viscosity concepts, in which the damage parameter was accounted for in …

Alloy Oxidation And Porcelain Fused To Alloy Interaction In Noble Alloy Systems, M. S. Bapna, H. J. Mueller

Cells and Materials

The oxidation and porcelain fusion characteristics of noble alloys containing a variety of minor oxidizable elements, including Cu, Sn, In, Ga, Mn, and Fe were investigated. Four porcelain alloys systems: a Pd-base alloy (Naturelle}, two Pd-Ag-based alloys (Jelstar and Acclaim}, and a high Au-alloy (SMG-3) were examined by scanning electron microscopy and energy dispersive spectroscopy after being heat treated and after being fused with porcelain. Internal oxidation of minor alloying elements occurred within several micrometers from the surface in all four alloys. Surface nodules as detected by other investigators for a Pd-Ag alloy were also detected in this study. Evidence …

A Quantitative Method Of Measuring Cell-Substrate Adhesion Areas, R. G. Richards, G. Rh Owen, B. A. Rahn, I. Ap Gwynn

Cells and Materials

Variability in measurements of the 'cell adhesion strength' of fibroblasts to substrates using mechanical disruption techniques causes difficulty in determining precisely the position, in the cytoskeleton-focal adhesion-matrix -substrate interface, where failure has occurred. In the present study, a quantitative in vitro procedure for measuring the total area and percentage of fibroblast adhesion to biomaterials, using the scanning electron microscope (SEM), is described. The amount of adhesion ofL929 and Balb/c3T3 fibroblasts to discs of stainless steel, commercially pure titanium, and polyethylene terepthalate (Thermanox) was quantified. Cells were fixed, stained with heavy metals, dehydrated and embedded in resin. The resin blocks were …

A Novel In Vitro Model To Study The Calcification Of Biomaterials, Q. Liu, J. Weng, J. G. C. Wolke, J. R. De Wijn, C. A. Van Blitterswijk

Cells and Materials

A novel in vitro model based on a solution mainly composed of sodium, calcium, chloride and phosphate ions, was developed to study the calcification of biomaterials at near physiological conditions. This model, due to its ability to quickly calcify the tested materials, is called Accelerated Calcification Solution (ACS). Polyactive ™ 30170, Polyactive™ 70/30 and its composites with nano-apatite were used as testing materials because of their known calcification behaviour. The results showed that Polyactive™ 70/30 and its composites could calcify in ACS in a relatively short period, while the polymer without filler failed to induce calcium phosphate precipitation in more …

Ultrastructural Observations Of Peri-Implant Mucosa Morphology Around Different Types Of Abutment In Humans, C. Piacentini, P. Lanzarini, R. Rodriguez Y Baena, S. Rizzo, C. Brusotti

Cells and Materials

Scanning electron microscopy (SFM) and transmission electron microscopy (TEM) were used to examine the morphological aspects of peri-implant mucosa around abutments of differing geometry (biconical and cylindrical) and of differing surface micromorphology. The samples were taken from seven patients who had undergone implant surgery at least one year prior to the study. In samples from biconical abutments, SEM of the sulcular epithelium showed that it consisted of flattened polygonal cells with a surface resembling a honeycomb. Superficial desquamation was rarely found. In contrast, in the samples from cylindrical abutments, the sulcular epithelium showed extensive desquamation and surface irregularity, but not …

Biological Response To Particulate Debris: In Vitro And In Vivo Studies, A. S. Shanbhag, J. E. Dowd, J. J. Jacobs, D. M. Tramaglini, T. T. Glant, J. Black, H. E. Rubash

Cells and Materials

In this study, we compared the results of a human monocyte in vitro model and a canine in vivo model, to evaluate the response to different types of particulate wear debris. Both the in vitro and in vivo studies demonstrated that titanium-6 aluminum-4 vanadium (TiAIV), ultrahigh molecular weight polyethylene (UHMWPE) and other particulate wear debris are stimulatory to macrophages and elicit release of several identifiable mediators involved in periprosthetic inflammation and bone resorption. Further, in the in vivo studies, these same particles initiated the formation of interfacial membranes which were histologically and biochemically similar to those seen in clinically failed …

Beta-Tricalcium Phosphate Resorption By Monocytes In Biphasic Calcium Phosphate: An In Vitro Study, Wolf Bohne, Jean A. Pouëzat, Dorothea Pouëzat, Guy Daculsi

Cells and Materials

A macroporous biphasic calcium phosphate (BCP) of 60.7% carbonated dense non-porous hydroxyapatite (HA)/39.3% dense microporous ß-tricalcium phosphate (ß-TCP) was immersed during 15 days in a supplemented a-MEM (minimal essential medium) solution with and without dog bone marrow cells obtained by punction. The aim of the study was to demonstrate the time-related changes in the BCP fractions by means of X -ray diffraction, infrared spectroscopy and scanning electron microscopy, and to investigate the cell populations. The HA/ß-TCP ratios varied according to immersion duration and cell presence. If any, there was a slight preponderance of ß-TCP …

The Effects Of Machining On Structure And Tribological Properties Of Ultra High Molecular Weight Polyethylene For Artificial Joint Prostheses, Jinshan Song

Masters Theses

Understanding the effect of machining on the structure and property of subsurface layer of ultra high molecular weight polyethylene (UHMWPE) can significantly facilitate the increase in longevity of artificial joints. This study was performed to investigate the machining effects on the polymeric structure and tribological properties. Machining parameters include cutting speed, tool feed rate and depth of cut. Temperature rise was studied during machining to assess the extent of thermal degradation due to machining. Polymeric structure of the semicrystalline polymer was characterized using differential scanning calorimetry (DSC) in terms of melting enthalpy, crystallinity and melting temperature. Surface texture and hardness …

Fractals, Surface Roughness, And Fracture Toughness Of Dental Composite And Unfilled Resin Fracture Surfaces, James L. Drummond

Cells and Materials

The intent of this project was to evaluate whether or not there exists a correlation between fractal dimension, surface roughness, and fracture toughness of an unfilled resin and a filled composite. The fracture surfaces of the unfilled resin and the filled composite were examined using atomic force microscopy (AFM) and a surface roughness measuring device. The specimens examined were aged in distilled water or air at 37°C for up to 12 months. Line scans of 1.4 µm for the atomic force microscope and 0.25 mm for the surface analyzer across the fracture surface were conducted on each specimen. Comparisons …

Surface Modifying Additives Reduce Thrombogenicity: An In Vitro And Clinical Evaluation, H. T. Spijker, J. Haan, R. Graaff, P. W. Boonstra, W. Van Oeveren

Cells and Materials

To improve the biocompatibility of biomaterials a new surface treatment has been described based on the addition of polysiloxane containing copolymers to the base polymer resin (surface modifying additives). In an in vitro and a clinical study, we compared the thrombogenicity of polyvinyl chloride (PVC) to PVC with these surface modifying additives (SMA).

In the in vitro study, adsorption of thrombin and fibrinogen, binding of platelets and platelet release were measured on the tubing and were found reduced on SMA-PVC.

For the clinical study, we examined tubing material and blood collected after cardiopulmonary bypass (CPB). Onto the tubing, the binding …

Osteoclast Differentiation In Cocultures Of Chondrogenic Cell Line Rcj 3.1c5.18 And Mouse Or Rat Bone Marrow: Dependence On Culture Substrate And Association With Alkaline Phosphatase Positive Marrow Stromal Cells, G. I. Anderson, J. N. M. Heersche

Cells and Materials

We investigated the formation of tartrate-resistant acid phosphatase positive (TRAP+) colonies and multinucleated cells (MNCs) in rat and mouse marrow cultures alone and cocultured with the chondrogenic cell line, RCJ3.1C5.18 on different substrata. In mouse marrow cultured in 35 mm dishes, few TRAP+ MNCs developed, while in rat marrow cultures, many TRAP+ MNCs, which possessed calcitonin receptors and resorbed bone, developed. In both rat and mouse cultures, TRAP+ MNC first appeared at Day 4 and grew in number up to Day 8. When both marrows were cocultured with RC3.1C5.18 cells, TRAP+ colony numbers increased relative to marrow alone. In marrow …

Irrigation Performance Measures: Efficiency And Uniformity, C. M. Burt, A. J. Clemmens, T. S. Strelkoff, K. H. Solomon, R. D. Bliesner, L. A. Hardy, T. A. Howell, Dean E. Eisenhauer

Biological Systems Engineering: Papers and Publications

It is essential to standardize the definitions and approaches to quantifying various irrigation performance measures. The ASCE Task Committee on Defining Irrigation Efficiency and Uniformity provides a comprehensive examination of various performance indices such as irrigation efficiency, application efficiency, irrigation sagacity, distribution uniformity, and others. Consistency is provided among different irrigation methods and different scales. Clarification of common points of confusion is provided, and methods are proposed whereby the accuracy of numerical values of the performance indicators can be assessed. This issue has two companion papers that provide more detailed information on statistical distribution uniformity and the accuracy of irrigation …

Transmission Electron Microscopical Study Of Fibroblast Attachment To Microtextured Silicone Rubber Surfaces, E. T. Den Braber, J. E. De Ruijter, H. J. E. Croes, L. A. Ginsel, J. A. Jansen

Cells and Materials

Cellular attachment has been suggested to be highly influenced by the micromorphology of the substratum surface. To test this hypothesis, smooth and microtextured silicone substrata were produced, which possessed parallel surface grooves with a groove and ridge width of 2.0 (SilD02), 5.0 (SilD05), and 10 µm (SilD10). Groove depth was approximately 0.5 µm. After culture of rat dermal fibroblasts (RDFs) on these substrata for 3 and 5 days, the samples were prepared and sectioned for transmission electron microscopy with a specially developed preparation technique. On the SilD02 and SilD05 surfaces, it was found that the RDFs attached to …

Peripheral Nerve Regeneration And Functional Nerve Recovery After Reconstruction With A Thin-Walled Biodegradable Poly(Dl-Lactide-Ε-Caprolactone) Nerve Guide, M. F. Meek, W. F. A. Den Dunnen, H. L. Bartels, A. J. Pennings, P. H. Robinson, J. M. Schakenraad

Cells and Materials

The aim of this study was to evaluate functional nerve recovery after reconstruction of a 1 em gap in the sciatic nerve of the rat, with a thin-walled biodegradable poly(DLLA-ε-CL) nerve guide. To evaluate both motor and sensory nerve recovery, walking track analysis and electrostimulation tests were carried out after implantation periods ranging from 3 to 26 weeks post-operatively. The first signs of functional nerve recovery could already be observed after 5 weeks. From the histological analysis, it could be concluded that most of the thin-walled nerve guides had collapsed. Despite collapsing, functional nerve recovery was relatively good after 26 …

Mechanism For Formation Of Lamellar Constituents In Grain-Refined Pd-Cu-Ga Dental Alloys, William A. Brantley, Zhuo Cai, John C. Mitchell, Stanley G. Vermilyea

Cells and Materials

Grain-refined Pd-Cu-Ga dental alloys solidify with a lamellar microstructural constituent that affects a variety of clinically relevant properties. While formation of this constituent has been attributed to eutectic solidification, an alternative mechanism of discontinuous precipitation has been proposed. Using a representative grain-refined Pd-Cu-Ga dental alloy, casting procedures involving two different rates of solidification were used: (a) A standard thin-walled coping configuration for a metal-ceramic restoration was cast into a room temperature mold, followed by rapid quenching into an ice-water mixture. (b) A thin plate specimen was cast into a standard elevated-temperature mold, with the same subsequent rapid quenching procedure. Neither …

Detachment Of Human Endothelial Cells Under Flow From Wettability Gradient Surfaces With Different Functional Groups, T. G. Ruardy, H. E. Moorlag, J. M. Schakenraad, H. C. Van Der Mei, H. J. Busscher

Cells and Materials

In this study, the position bound adhesion, spreading and detachment under flow of human umbilical cord endothelial cells (HUVEC) was studied on a dichlorodimethylsilane (DDS), dimethylocta-decylchlorosilane (DOCS) and tridecafluor-1,1,2,2-tetrahydrooctyl-1-dimethylchlorosilane (TFCS) wettability gradient on glass. Gradient surfaces were prepared by the diffusion method and characterized by the Wilhelmy plate technique for their wettability and by X-ray photoelectron spectroscopy (XPS) for their chemical composition. Quantitative analysis of the cellular response on the wettability gradient surfaces showed that the position bound cellular response was influenced by wettability for each type of gradient in a different way. On DDS-wettability gradients, cells withstood flow best …